Cities: Skylines is a game developed by the developers for 8 years, and over the years, it has significantly changed. With all the DLC, the base version is very different in terms of gameplay mechanics, objects, visuals, and more from the game. The most recent updates for Cities: Skylines will be available in May this year.
Cities: Skylines' authors outline a roadmap for the next months. Six sets will be released in March and May, as well as an unspecified new content update called Hubs and Transport.
Recall that the game Cities: Skylines 2 has already been released, and it should be released this year and immediately following its release in Game Pass.